Harry S. Courtney, PhD, professor in the Department of Medicine at UTHSC, has received a grant totaling $126,000 from the National Institute of Allergy and Infectious Diseases, a subsidiary of the National Institutes of Health.

Harry S. Courtney, PhD, professor in the Department of Medicine at the University of Tennessee Health Science Center (UTHSC), has received a grant totaling $126,000 from the National Institute of Allergy and Infectious Diseases, a subsidiary of the National Institutes of Health. The award will fund research on streptococcal infections. The study titled, “Role of M-Related Protein and IgG Interactions in Virulence of S. pyogenes,” will be conducted over a two-year period.

The focus of Dr. Courtney’s research is on molecular mechanisms of group A streptococcal infections. Group A streptococci, which is caused by the bacterium Streptococcus pyogenes, produces an array of diseases ranging from mild and self-limiting infections of the throat and skin to highly invasive diseases with significant rates of morbidity and mortality. The incidence of severe, invasive infections by S. pyogenes has been increasing throughout the world, and it is the ninth-leading cause of mortality among all microbial pathogens worldwide. Infections due to S. pyogenes are limited to humans, but the basis for why people are the target host is relatively unknown.

“This award will provide the opportunity to make meaningful contributions to our understanding of the pathogenesis of group A streptococcal infections,” said Dr. Courtney. “It will hopefully identify a new target for vaccine development as well.”

Currently, the rodent model is used extensively to study streptococcal infections. However, rodents are naturally resistant to S. pyogenes, thus large doses are required to initiate infections. This award will allow Dr. Courtney and his research team to examine the role of IgG*,which are antibody molecules, binding to the streptococcal surface protein — M-related protein (Mrp) — as it relates to virulence and host specificity. The team will then use their findings to determine if the passive transfer of human IgG to mice will increase their susceptibility to S. pyogenes. Knowing this would improve the animal model by allowing investigators to avoid using high doses that may obscure results.

The findings from this study relating to Mrp-IgG interactions may provide more insight into host specificity of streptococcal infections and lay the foundation for developing therapies or vaccines to block this interaction and prevent infections from this bacteria.

The National Institutes of Health (NIH), the nation’s medical research agency, includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic, clinical, and translational medical research, and is investigating the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit www.nih.gov.

*Immunoglobulin G (IgG) – Antibody molecules that are composed of four peptide chains